Two photographs of a peripheral blood smear are submitted for review .

The smears are from a 9-month-old baby with a heart valve replacement.

• In the upper photograph is a nucleated RBC and platelets are decreased. Nucleated red cells and occasional giant platelets indicate an active marrow response.
• In the process of forcing blood cells through the heart valve, erythrocytes are damaged, schistocytes are formed, and platelets are destroyed leading to thrombocytopenia.
• In the lower field are schistocytes, acanthocytes, echinocytes (burr cells), spherocytes, and the absence of platelets.
• The presence of burr cells could represent an artifact of smear preparation, but with the history of valve replacement, the red cell changes are likely the result of red cell damage as the cells circulate through the new valve. This situation is described as Waring Blender Effect because of damage to blood cells passing through the new valve, looking as if they had suffered the onslaught of a blender.
• Target cells and mild hypochromia may reflect iron deficiency through the loss of iron from destruction of RBC's.
• Iron loss through red cell destruction may be reflected in some hypochromia.